Orientation-Dependent Friction in Liquid Crystals

The meaning of the rotational friction and diffusion tensor in Liquid crystalline phases characterized by anisotropic viscosities is discussed, by generalizing the hydrodynamic Stokes-Einstein relationships. Corrections due to the viscosity anisotropy effects to the rotational correlation times, relevant for the interpretation of magnetic and dielectric relaxation experiments, have been computed by solving the appropriate Fokker-Planck equation